This is the same issue I had with my GDM-FW9011. Haven’t found a fix it was doing this for 2-3 years and now it never gets to a clear screen. Always that green screen with lines then it auto shuts off.
Here’s a video of mine:
The flashing light is most likely the Auto Brightness shutoff as the screen gets too bright.
If you find a fix let me know.
Have you tried to have all this at the same time BEFORE turning it ON:
- lower contrast and brightness in OSD to zero
- use white color background
then turning it ON and also open the OSD menu as soon possible (even though you can't see it because it's still all black during the initial boot up).
Then wait until the image stabilizes (darkens) and there are no more retrace lines and turn back up the contrast and brightness.
It may take a few reboots in case you will not have enough time to lower the contrast and brightness down before it shuts off.
I need to do this on my F520 every time before I turn it OFF otherwise I get similar looking issues (no retrace lines though) when I start it back up the next day. And my unit is WPB calibrated - if you did not do WPB and you can do that then surely do that.
You are correct about it being shut off by a safety mechanism that basically detects there is more electrons in the tube than the unit can suck away. During boot the high-voltage is not at it's peak and it takes 20-60 minutes to stabilize at peak. Until then the picture appears lighter/washed out because the electrons are bouncing around in the tube (and hitting the "screen" again and again at off angles. In ideal world, the electron sent by cathode (and deflected by electromagnets) hits the "screen" and then bounces from that to the tube somewhere which is coated with conductive coating that is connected to the high-voltage anode. This is the whole reason why there is high-voltage in these monitors, you need to garbage collect the negatively charged electrons to the positively charged anode. And you need a lot of this power hence the high-voltage. So again, if this garbage collection fails, there will be electron house party in the tube and you wouldn't want that so it shut itself off as a precaution. This is just my limited understanding after using these babies for some time now.